Gear planing machine



Dec. 2, 1947. E. LAESSER GEAR PLANING MACHINE Filed May 26, 1944 2Sheets-Sheet l law/22W? Patented Dec. 2, 1947 GEAR PLANING MACHINE EmilLaesser, Zurich, Switzerland, assignor to Maag-Zahnriider 11nd-Maschinen Aktiengesellschaft, Zurich, Switzerland Application May 26,1944, Serial No. 537,491

In Germany April 29, 1943 1 3 Claims.

The present invention relates to gear planing machines operating on theprinciple of relative rolling motion of parts connected with a rack liketool.

Several constructions of machines of this kind are already known. In allof these the tool is held by a pivotal holder which is mounted on arectilinearly movable ram. The detaching of cuttings takes place inmachines of this kind without exception while the ram moves in one orthe other direction. The ineffective return stroke of the ram is usuallyeffected at increased speed and the holder carrying the rack like toolis pivotally displaced somewhat rearwardly in order to let the toolfreely pass by the work. Therefore, the time required by the ram toperform its return stroke must be considered as lost in the operation ofthe machine.

The present invention has for its object a gear planing machine in whichin the tool carrier ram a tool holder is rotatably mounted which iscontrolled by the movements of the tool carrier ram. in such manner,that the tool performs a pivotal movement in the course of each strokeof the tool carrier ram in order to permit of the detaching of cuttingsto take place in either direction of movement of the ram.

For the purpose of effecting the detaching of cuttings in bothdirections of movement, a tool which cuts in both directions of movementof the ram is clamped to the tool carrier ram and which is pivotallydisplaced at the beginning of each ram stroke until the tool holder hitsa stop fOr the tool carrier ram. Consequently, as a loss of time onlythe period is yet to be considered in which the tool moves beyond thework. Further, it is possible to carry on the planing work only in oneor the other direction of movement of the ram, as desired, by merelychanging over a stop means. This may at times be necessary, for example,in planing stepped gears not having sufficient spare room for a toolwith two opposed cutting edges to pass out of engagement with the work.With conventional gear planing machines, operating by means of chasingtools, in general, Working is possible only in one direction of movementof the ram.

A form of a machine according to the present invention is illustrated byway of example only in the accompanying drawings in which Fig. 1 shows aschematic elevation partly in section of this machine;

Fig. 2 is a top plan view of a tool carrier ram;

Fig. 3 is a sectional view of the tool carrier ram disclosing thepivotal tool holder in position for planing in the downward direction;

Fig, 3a is a view indicating the corresponding position of the stoplever;

Fig. 4 is a view similar to Fig. 3 showing the ram in position forplaning upwardly.

Fig. 5 is a view similar to Fig. 3 showing the tool holderand the stoplever in their positions for planing in one direction of movement of theram only, the ram being shown while performing the return stroke;

Fig. 6a is a view indicating the position of the stop lever in positionfor planing in the downward direction of movement of the ram, and

Fig. 6b is a view similar to Fig. 6a but concerning the planing upwards.

Referring to Fig. 1, on the bed I of the machine a ram or slide 2 ismounted which is movable in the direction toward the toolfor applyingthe work to the latter and vice versa. A further slide 33mounted on theslide 2 is provided with a round work table 4 and is arranged forpeforming the relative rolling motion, as required for the planing,together with said table. The table 4 carries the work 5 in clampingengagement therewith. On a standard 6 of the' machine bed the toolcarrier ram 1 reciprocates up and down by control of a crank 8. hasdriving movement imparted thereto via gear wheel drives 9, l0 and II, I2by a coupling l3 which is operatively connected with a motor (notshown). I

In the tool carrier ram 1 (Figs. 2 to 5) is rotatably mounted a holder Mfor a rack like tool 15. In Fig. 3 the machine is shown in the conditionfor planing in the downward direction of ram movement, whereas Fig. 4shows the condition for planing upwards. For obtaining these conditionsthe holder I4 is pivotally displaced in time with each stroke through anangle a. To this end the tool holder is provided with a tooth gap orsocket is into which projects a tooth or nose H on a latch l8 which alsois provided with a tooth gap, at l9. With the latter gap interengages atooth 20 on a lever 2|. The other arm of this lever which is fulcrumedon an axis 22 is provided with a similar tooth gap 23 with whichcooperates a tooth 24 on a friction coupling. This coupling isconstituted by a cam 26 which is arranged for swinging about an axis 25and is provided with a loose sliding shoe 21 which is urged outwardly bya spring 28 and cooperates with the inner wall of a sleeve 29 which isrotatably mounted in the ram 1. The sleeve 29 carries an outer toothsystem which meshes This crank 3 with a rack 30 which is secured to thestandard 6.

In Fig. 3 the machine is shown to start out on a planing stroke in thedownward direction. The sleeve 29 has rotational movement impartedthereto by mutual rolling movement between its tooth system and the rack30 in the counterclockwise direction. Due to friction action between thesliding shoe 2! and the sleeve the cam 26 is first turned along, therebypushing the latch l8 toward the left by means of the lever 2|. The latchthus rotates the holder l4 until the side wall a of a recess 3| meetswith a stop member 32 which is tenoned in the ram 1 so that the cam 25comes to a standstill.

With the holder l4 in this position the tool l5 has arrived in itseffective planing position so that the detaching of cuttings can begin.The consequent pressure effect on the cutting edge of the tool istransmitted via the wall a to the stop member 32 which thus prevents thetool from further pivoting toward above. Onthe termination of theworking stroke when the tool has completely moved out of the embrace ofthe tooth gap the direction of movement of the ram is changed overtoward above (Fig. 4.)

The sleeve 29 then rotates in the clockwise direction so that the latchI8 moves toward the right. By this means the holder 14 is pivotallydisplaced through an anguar range at until the stop member 32 meets withthe wall 1). During the planing operation in both directions of rammovement the stop lever 33 remains in median position (Fig. 3a) so thatneither of two side walls 0, d of a recess 35 in the latch It! comes incontact with a stud 34.

A further functioning of the machine consists in that planing can beeffected in either of two directions of ram movement as desired, atwill. For this purpose the stop lever 33 need merely be changed overin'corresponding manner (Figs. 5 and 6). Figs. 5 and 6a show thecondition for planing in the downward'direction of ram movement whilethe stud 34 is situated in its extreme left hand position.

If the ram then moves ineffectively in the upward direction (Fig. 5) thelatch I8 is shifted toward the right until the wall face of the recess35 meets with the stud 34 the position of which is so chosen that withthe latch in corresponding position the tool I is situated exactly inmedian position. The cutting edges are then pivotally retracted fromcutting position a suflicient amount for being adapted to move past thetooth flanks of the work.

The next following working stroke in the downward direction rotates thesleeve 29 before the tool has arrived at the gear so that the holder I4is moved into position of operation, as shown in Fig. 3, in which thestud 34 projects into the recess 35 without touching either of the twowall faces 0, d.

If, however, it is desired to effect planing work in the upwarddirection of ram movement the stop lever 33 must be changed over asshown in Fig. 6b. In this case the face d bears on the stud 34 duringthe downward movement of the ram so that the latch 18 and the tool arecompelled to assume their positions as shown in Fig. 5 again. In thisinstance by the working stroke in the upward direction the position ofthe tool as shown in Fig. 4 is first brought about, on which follows thedetaching of cuttings and then the changing over of the tool holder forreturn movement. For

the planing in one direction of ram movement only. a tool with twoopposed cutting edges as well as a conventional tool with only onecutting edge can be used.

Obviously a tool with two opposed cutting edges may be formed by twotools having a single cutting edge only.

I claim:

1. In a gear planing machine a reciprccatory tool carrier ram, a tooladapted to cut in either direction of movement of the ram, a tool holdermounted insaid ram to rotate about an axis extending perpendicularly toand laterally displaced from the line of cutting and holding said tool,drive means including latch means drivingly connected between said ramand said rotary tool holder for oscillating said tool holder about itsaxis in dependency on the direction of the reciprocating movement ofsaid ram, stop means arranged on said ram for engagement with the toolholder for limiting the extent of oscillation in both directions, andfriction coupling means arranged in the drive of said latch means andthereby in the oscillation drive of the tool holder, to provide foryielding in said oscillation drive when the tool holder engages saidstop in either extremity of oscillation.

2. In a gear planing machine, a reciprccatory tool carrier ram, a tooladapted to cut in both directions of movement of the ram, a tool holdermounted in said ram to rotate about an axis extending perpendicularly toand laterally displaced from the line of cutting and holding said tool,drive means including latch means drivingly connected between said ramand said rotary tool holder for oscillating said tool holder about itsaxis in dependency on the direction of reciprocating movement of saidram, friction coupling means arranged in the drive of said latchingmeans and thereby in the oscillation drive of the tool holder, toprovide for yielding in said oscillation drive when the tool holderengages said stop in either extremity of oscillation, and an adjustablestop means for limiting the movement of said latch means forinterrupting the movement thereof when said tool is in median positionfor detaching cuttings from said work by said tool in one direction ofmovement of said ram only, and

for releasing said latch means for said tool to cut in both directionsof ram movement, said friction coupling also serving to provide yieldingin the oscillation drive when the adjustable stop means is adjusted tolimit movement of the latch means.

3. In a gear planing machine, a reciprccatory tool carrier ram, a tooladapted to cut in either direction of movement of the ram. a tool holdermounted in said ram to rotate about an axis extending perpendicularly toand laterally displaced from the line of cutting and holding said tool,drive means including latch means, nose and socket drive meansinterposed between said latching means and said rotary tool holder,friction coupling means in said drive for allowing yielding in saiddrive when said tool holder engages the stop means in either directionof oscillation, levers interposed between said friction coupling meansand said latch means for actuating said latch means topivotally displacesaid tool holder as limited by engagement of said holder with said stopmeans at each stroke of said ram, and an adjustable stop means forlimiting the movement of said latch means by interrupting said movementwhen said tool is in REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Name Date Angus May 6, 1884 Kuwada Sept. 14, 1909Eggers Oct. 22, 1912 Maag Jan. 7, 1919 FOREIGN PATENTS Country DateFrance Jan. 25, 1929

